1. Field of the Invention
The present invention relates, in general, to controlled droplet applicators for use in applying liquid chemicals and the like to crops.
2. Description of the Prior Art
Liquid chemicals are typically sprayed on crops, bare ground and the like as pre- and/or post-emergence herbicides, fungicides and insecticides. The spraying may be accomplished with the aid of airplanes, tractors, and the like. A relatively recent development in this field has been controlled droplet applicators (CDAs). The CDAs provide a substantially uniform size liquid droplet to allow better control of the spraying. Such CDAs typically include one or more rotary atomizers for reducing liquid into a fine spray having substantially uniform sized droplets. More specifically, liquid is typically fed into the center of the atomizer and subsequent rotation of the atomizer causes the liquid to migrate to the periphery of the atomizer and be discharged therefrom as a spray of droplets. Bals, U.S. Pat. No. 4,225,084 discloses a rotary atomizer in the shape of a hollow truncated cone having a tooth periphery and internal radial grooves leading to the gaps between the teeth. The cone of the '084 patent is rotatably driven by an electric motor or by means of a turbine (Pelton wheel) attached to the central shaft of the cone above the body of the cone with fluid being sprayed against the turbine with sufficient velocity to cause the turbine and cone to rotate (the fluid then falls from the turbine into the cone where it is atomized). It is known that some such rotary atomizers for use in aerial spraying have been provided with air turbines whereby the movement of the air past the air turbines as the plane is moving causes the atomizers to rotate. None of the above prior art, taken as a whole, disclose or suggest the present invention.